The Section of Maternal-Fetal Medicine at Northwestern University Medical School has a strong interest in continuing as a member of the multicenter Network of Maternal-Fetal Medicine Units. We again wish to participate in clinical trials utilizing common protocols, with emphasis on the areas of preterm delivery and other conditions leading to neonatal mortality and morbidity. This application describes a plan for the cooperative efforts of the MFM units at both Northwestern Memorial Hospital (NMH) and at Evanston Northwestern Healthcare (ENH) in Network activities. NMH and ENH are the two primary teaching affiliates for the Northwestern University Feinberg School of Medicine. Combined activities of the Departments of Obstetrics and Gynecology at these two facilities include education of medical students and residents, as well as research. We have demonstrated our capabilities in jointly conducting and participating in randomized trials and multicenter studies that involved detailed study procedures for both pregnant women and their neonates. During this current cycle of the MFMU network, ENH was added as a Northwestern recruitment site through a subcontract arrangement, and recruitment is currently occurring on two network protocols. The plan for this submission is for cooperation in network trials to continue and to be expanded to all ongoing studies. We believe our strengths lie in our large patient base in two academic facilities with a proven record of cooperation in research, and our committed, innovative faculty capable of contributing new directions to the development and prioritization of a research agenda for the Network. Furthermore, we have the requisite research infrastructure that enables the recruitment and follow-up of not just high-risk patients, but private as well as indigent patients that will maximize the generalizability of MFMU Network results to the entire population at risk for adverse perinatal outcomes. We are committed to working cooperatively with member units and network staff in the areas of study design, protocol implementation, patient recruitment, data analysis and publication. Relevance to public health-We plan to recruit patients from a diverse patient population at two large academic medical centers to participate in multicenter clinical trials investigating important problems in clinical obstetrics, such as the persistent high rate of preterm birth in this country. We also plan to participate in study design and other functions of the network in a cooperative fashion. In this way we hope to provide answers to current clinical dilemmas, which will result in better patient care and improved clinical outcomes for both neonates and their mothers.